Detergent composition comprising coated bleach particle

ABSTRACT

The present invention relates to detergent compositions containing incompatible ingredients, like enzymes and bleach, which can be used to clean various surfaces including but not limited to, hard surfaces as well as fabrics, clothes, carpets, wherein a bleach is encapsulated in coating digestible by an enzyme present in the composition.

The present invention relates to detergent compositions containingincompatible ingredients, like enzymes and bleach, which can be used toclean various surfaces including but not limited to, hard surfaces aswell as fabrics, clothes, carpets and the like, wherein a bleach isencapsulated in a coating digestible by an enzyme present in thecomposition.

Detergent compositions for removal or cleaning stains on fabrics and/orhard surfaces typically contain bleaching agents. These can be dividedinto two groups: oxygen bleaches (typically peroxides) and halogenbleaches (typically chlorine bleaches). Their action is based on theoxidation of the molecules present in the stains.

Besides this, detergent compositions typically contain enzymes,typically from the groups of proteases, amylases and lipases. Enzymesare proteins and are susceptible to oxidative degradation such as fromthe bleaches that are present in the composition. It is known in the artthat, though very effective to remove stains, bleaching agents alsopresent a number of drawbacks to product stability when used. Forexample, bleaching agents, when in contact with perfumes or enzymes,partially or totally inactivate these molecules, thus causing a loss ofperformance. The incompatibility of these ingredients is a problem wellknown in the art and certain solutions have been found, such as in theuse of discrete layers in laundry tablets. However, in the field ofliquid detergents segregation is more difficult and the usual solutionsare to encapsulate one or the other mutually incompatibleingredients—typically to encapsulate the bleach since that it isunstable in the presence of water.

Furthermore, it is known in the art that bleaching agents may reduce theeffectiveness of enzymes on some stains because they chemically modifythe structure of the stains thus inhibiting, partially or totally, thecapability of the enzyme to attack the stains themselves.

The present invention thus provides a coating for bleaching agents whichis digestible by an enzyme present in the composition which is stable inthe product environment whilst easily removable in the wash bath, thusmaking them usable in the formulation of detergents containing enzymesand other ingredients incompatible with bleach.

The coated bleaching agents according to the present invention may beuseful in any laundry and hard surface cleaning application, e.g., as inlaundry detergents, laundry additives or dish washing detergents. Aparticular advantage of the present invention is that the material usedfor the coating of the bleach is fully biodegradable, thus making itecologically acceptable.

Another advantage of the present invention is that it allows theformulation of stable detergent compositions containing incompatible rawmaterials (typically enzymes and bleach), thus improving the cleaningperformance of the formulation itself.

Yet another advantage of a coating described in the present invention isthat it is degraded by the enzymes present in the detergent compositionin the wash bath, making bleach available only once the enzymes have atleast started their action and thus reducing the interference betweenthe two actives.

U.S. Pat. No. 5,589,370 Unilever describes a continuous process forcuring capsules which contain “sensitive ingredients”, typically enzymesare described as the material encapsulated using a suitable crosslinking polymer material. EP0554359 Unilever describes the use ofcationic proteins of MW of 1 k to 50 k as being useful in stabilisingenzymes or bleach compounds in heavy duty laundry detergent liquids.EP0653485 Unilever describes enzyme and bleach containing capsules.

According to the present invention there is provided a detergentcomposition, preferably a liquid, comprising an enzyme and a coatedbleaching, wherein the coating material of the bleaching agent is asubstrate for the at least one enzyme, preferably the material beingselected from the group consisting of protein, either of animal orvegetal origin, starch, fat and a mixture thereof, preferably thematerial is a protein.

Ideally the enzyme is separated from the coating of the bleaching agent,for example, by being coated or physically segregated.

Preferably the enzyme is inactive in the detergent but active in thewash. Enzymes may be inactive due to the presence of a coating which issensitive to a change of one or more physical parameters, like pH,temperature, osmotic pressure or ionic strength.

Preferably the composition according to the present invention is aliquid, and ideally is an aqueous liquid. Thus the compositionpreferably has a water content of from 5% to 99%, more preferably from10% to 95%, more preferably from 20% to 90% by weight of thecomposition.

The compositions according to the present invention ideally have a pHfrom 1 to 14, preferably from 2 to 14 and more preferably from 4 to 12.

Alternatively the composition may be a solid such as a powder or ashaped article, such as a tablet. If the product is a solid then theenzyme is preferably physically separated from the coated bleachingagent.

The compositions according to the present invention ideally containenzymes from the classes of proteases, lipases and amylases orcombinations thereof.

Said bleaching agents are preferably coated with a protein film havingthickness from 10μ to 1000μ, more preferably from 50μ to 500μ and morepreferably from 100μ to 300μ.

Proteins suitable for coating can be selected are chosen from the groupconsisting of vegetable proteins, including but not limited to gluten,soybean, or a combination thereof, and from the group consisting ofanimal proteins, including but not limited to albumin, gelatin,lactoproteins, or a combination thereof.

Coating characteristics like hydrophobicity, colour, resistance tobacteria and fungi can be provided by adding to the protein additiveslike hydrophobic substances, colourants, bactericide or fungicidesubstances.

Hydrophobic substances can be used to reduce water permeability of thecoating. They can be chosen from oils, waxes, emulsifiers and mixturesthereof.

Colourants and dyes can be used to provide the coating with differentcolours. They can be chosen from pigments, dyes and mixtures thereof.

Bactericide and fungicide substances can be optionally used to increasethe resistance of the coating to the attack of microorganisms.

Bleaching Agent

The composition according to the present invention ideally contains ableaching agent from the classes of halogen bleaches or oxygen bleaches,having average size from 100μ to 2500μ, more preferably from 500μ to2000μ and more preferably from 700μ to 1500μ.

In one preferred aspect the oxygen-releasing bleaching agent contains ahydrogen peroxide source and an organic peroxyacid bleach precursorcompound. The production of the organic peroxyacid occurs by an in situreaction of the precursor with a source of hydrogen peroxide. Preferredsources of hydrogen peroxide are inorganic perhydrate bleaches.

Inorganic Perhydrate Bleaches

Suitable hydrogen peroxide sources include the inorganic perhydratesalts.

The inorganic perhydrate bleaches or salts thereof are normallyincorporated in the form of the sodium salt at a level of from 1% to 40%by weight, more preferably from 2% to 30% by weight and most preferablyfrom 5% to 25% by weight of the compositions.

Examples of inorganic perhydrate bleaches and their salts includeperborate, percarbonate, perphosphate, persulfate and persilicate salts.The inorganic perhydrate are normally the alkali metal salts. Theinorganic perhydrate bleach may be included as the crystalline solidwithout additional protection.

Sodium perborate can be in the form of the monohydrate of nominalformula NaBO₂.H₂O₂ or the tetrahydrate NaBO₂.H₂O₂.4H₂O.

Alkali metal percarbonates, particularly sodium percarbonate arepreferred perhydrates for inclusion in compositions in accordance withthe invention. Sodium percarbonate is an addition compound having aformula corresponding to 2Na₂CO₃.3H₂O₂, and is available commercially asa crystalline solid. Sodium percarbonate, being a hydrogen peroxideaddition compound tends on dissolution to release the hydrogen peroxidequite rapidly which can increase the tendency for localised high bleachconcentrations to arise. Therefore, an additional advantage of theinvention is provided by the coating to the bleach providing controlledrelease of the bleach (by “controlled” we mean that release is noteffected immediately upon use).

Peroxyacid Bleach and Precursors

Organic peroxy acids or the precursors therefor may also be utilized aspart of the bleach agent. The peroxyacids usable in the presentinvention are solid and, preferably, substantially water-insolublecompounds. By “substantially water-insoluble” is meant herein awater-solubility of less than about 1% by weight at ambient temperature.In general, peroxyacids containing at least about 7 carbon atoms aresufficiently insoluble in water for use herein.

Typical monoperoxy acids useful herein include alkyl peroxy acids andaryl peroxyacids such as:

(i) peroxybenzoic acid and ring-substituted peroxybenzoic acids, e.g.peroxy-alpha-naphthoic acid;

(ii) aliphatic and substituted aliphatic monoperoxy acids, e.g.peroxylauric acid and peroxystearic acid;

(iii) phthaloyl amido peroxy caproic acid (PAP).

Typical diperoxy acids useful herein include alkyl diperoxy acids andaryldiperoxy acids, such as:

(iv) 1,12-diperoxydodecanedioic acid (DPDA);

(v) 1,9-diperoxyazelaic acid;

(vi) diperoxybrassylic acid; diperoxysebacic acid anddiperoxyisophthalic acid;

(vii) 2-decyldiperoxybutane-1,4-dioic acid.

Peroxyacid bleach precursors are well known in the art. As non-limitingexamples can be named N,N,N′,N′-tetraacetyl ethylene diamine (TAED),sodium nonanoyloxybenzene sulphonate (SNOBS), sodium benzoyloxybenzenesulphonate (SBOBS) and the cationic peroxyacid precursor (SPCC) asdescribed in U.S. Pat. No. 4,751,015.

Metal-Containing Bleach Catalyst

The bleaching agent described herein may additionally contain as apreferred component, a metal containing bleach catalyst. Preferably themetal containing bleach catalyst is a transition metal containing bleachcatalyst, more preferably a manganese or cobalt-containing bleachcatalyst, but may be based upon iron or copper. Ideally the bleachcatalyst is found with the other components of the bleaching agentinside the capsulate or it may be found in the liquid of the detergentcomposition or in the form of a second encapsulate.

A suitable type of bleach catalyst is a catalyst comprising a heavymetal cation, such as copper, iron cations, an auxiliary metal cationhaving little or no bleach catalytic activity, such as zinc or aluminiumcations, and a sequestrant having defined stability constants for thecatalytic and auxiliary metal cations, particularlyethylenediaminetetraacetic acid, ethylenediaminetetra(methylenephosphonic acid) and water-soluble salts thereof. Suchcatalysts are disclosed in U.S. Pat. No. 4,430,243.

Preferred types of bleach catalysts include the manganese-basedcomplexes disclosed in U.S. Pat. No. 5,246,621 and U.S. Pat. No.5,244,594. Others are described in European patent applicationpublication no. 549,272. Other ligands suitable for use herein include1,5,9-trimethyl-1,5,9-triazacyclododecane,2-methyl-1,4,7-triazacyclononane, 2-methyl-1,4,7-triazacyclononane,1,2,4,7-tetramethyl-1,4,7-triazacyclononane, and mixtures thereof.

Chlorine or Bromine Releasing Bleaches

The bleaching agent to be encapsulated in the coating may be a chlorine-or bromine-releasing agent. Among suitable reactive chlorine- orbromine-oxidizing materials are heterocyclic N-bromo and N-chloro imidessuch as trichloroisocyanuric, tribromoisocyanuric, dibromoisocyanuricand dichloroisocyanuric acids, and salts thereof with water-solubilisingcations such as potassium and sodium. Hydantoin compounds such as1,3-dichloro-5,5-dimethyl-hydantoin are also suitable.

Dry, particulate, water-soluble anhydrous inorganic salts are likewisesuitable for use herein such as lithium, sodium or calcium hypochloriteand hypobromite. Chlorinated trisodium phosphate is another corematerial. Chloroisocyanurates are, however, the preferred bleachingagents. Potassium dichloroisocyanurate is sold by Monsanto Company asACL-59™. Sodium dichloroisocyanurates are also available from Monsantoas ACL-60™, and in the dihydrate form, from the Olin Corporation asClearon CDB-56™, available in powder form (particle diameter of lessthan 150 microns); medium particle size (about 50 to 400 microns); andcoarse particle size (150-850 microns). Very large particles (850-1700microns) are also found to be suitable for encapsulation.

Enzyme Coating

In one embodiment of the invention the enzyme may also be coated. Arequirement of the feature of the invention is that the enzyme coatingdissolves easily to aid the dissolution of the bleaching agent coating.The enzyme, preferably a protease, may be coated by any suitable knownmeans or any suitable material. Examples of such are provided below

A suitable coating material providing in product stability comprisesmixed salt of a water soluble alkali metal sulphate and carbonate. Suchcoatings together with coating processes have previously been describedin GB-1,466,799. The weight ratio of the mixed salt coating material topercarbonate lies in the range from 1:200 to 1:4, more preferably from1:99 to 1:9, and most preferably from 1:49 to 1:19. Preferably, themixed salt is of sodium sulphate and sodium carbonate which has thegeneral formula Na₂SO₄.n.Na₂CO₃ wherein n is from 0.1 to 3, preferably nis from 0.3 to 1.0 and most preferably n is from 0.2 to 0.5.

Another suitable coating material providing in product stability,comprises sodium silicate of SiO₂:Na₂O ratio from 1.8:1 to 3.0:1,preferably 1.8:1 to 2.4:1, and/or sodium metasilicate, preferablyapplied at a level of from 2% to 10%, (normally from 3% to 5%) of SiO₂by weight of the inorganic perhydrate salt. Magnesium silicate can alsobe included in the coating. Coatings that contain silicate and boratesalts or boric acids or other inorganics are also suitable.

Suitable coating materials include triglycerides (e.g. partially)hydrogenated vegetable oil, soy bean oil, cotton seed oil) mono ordiglycerides, microcrystalline waxes, gelatin, cellulose, fatty acidsand any mixtures thereof.

Suitable coating techniques are described below for the bleaching agent.

Detergent Enzymes

The additional detergent compositions can further comprise one or moreenzymes which provide cleaning performance, fabric care and/orsanitisation benefits.

Said enzymes include one or more enzymes selected from proteases,cellulases, hemicellulases, peroxidases, bluco-amylases, amylases,xylanaes, lipases, phospholipases, esterases, cutinases, pectinases,keratanases, reductases, oxidases, phenoloxidases, lipoxygenasesliginases, pullulanases, tannases, pentosanases, malanases,R-glucanases, arabinosidases, hyaluronidase, chondroitinase, laccase ormixtures thereof.

An essential feature of the invention is that at least one enzyme isused that is capable of digesting the material used to encapsulate thebleach.

A preferred combination is a detergent composition having cocktail ofconventinal applicable enzymes like amylase, lipase cutinase and/orcellulase in conjunction with one or more plant cell wall degradingenzymes.

The cellulases usable in the present invention include both bacterial orfungal cellulases. Preferably, they will have a pH optimum of between 5or 12 and an activity above 50 CEVU (Cellulose Viscosity Unit). Suitablecellulases are disclosed in U.S. Pat. No. 6,107,8384 and WO 96/02653which discloses fungal cellulase produced respectively from Humicolainsolens, Trichoderma, Thielavia and Sporotrichum. EP 739 982 describescellulases isolated from novel Bacillus species. Suitable cellulases arealso disclosed in GB-A-2.075.028; GB-A-2.095.275; DE-OS-2.247.832 and WO95/26398.

Examples of such cellulases are cellulases produced by a strain ogHumicola insolens (Humicola grisea var. thermoidea), particularly theHumicola strain DSM 1800.

Other suitable cellulases are cellulases originated from Humicolainsolens having a molecular weight of about 50 KDa, an isoeletric pointof 5.5 and containing 415 amino acids; and a 43 kD endoglucanase derivedfrom Humicola insolens, DSM 1800, exhibiting cellulase activity; apreferred endoglucanase component has the amino acid sequence disclosedin PCT Patent Application No. WO 91/17243.

Also suitable cellulases are the EGIII celulases from Trichodermalongibrachiatum described in WO 94/21801, Genencor, published Sep. 29,1994. Especially sutiable cellulases are the cellulases having colourcare benefits.

Examples of such cellases are cellulases described in European patentapplication No. 91202879.2, filed Nov. 6, 1991 (Novo). Carezyme andCelluzyme (Novo Nordis, A/S) are especially useful. See also WO 91/17244and WO 91/21801. Other suitable cellulases for fabric care and/orcleaning properties are described in WO 96/34902, WO 96/17994 and WO95/24471.

Said cellulases are normally incorporated in the detergent compositionat levels from 0.0001% to 2% of pure enzyme by weight of the detergentcomposition.

Peroxidase enzymes are used in combination with oxygen sources, egpercarbonate, perborate, persulfate and hydrogen peroxide, and with aphenolic substrate as bleach enhancing molecule.

They are used for “solution bleaching”, i.e. to prevent transfer of dyesor pigments removed from substrates during wash operations to othersubstrates in the wash solution. eroxidase enzymes are known in the art,and include, for example, horseradish peroxidase, ligninase andhaloperoxidase such as chloro- and bromo-peroxidase.Peroxidase-containing detergent compositions are disclosed, for example,in WO 89/099813 and WO 89/09813. Also suitable is the laccase enzyme.

Enhancers are generally comprised at a level of from 0.1% to 5% byweight of total composition. Preferred enchancers are substitutedphenthiazine and phenoxasine 10-phenothiazinepropionic acid (PPT),10-ethylhenothiazine-4-carboxylic acid (EPC), 10-phenoxazinepropionicacid (POP) and 10 methylphenoxazine (described in WO 94/12621) andsubstituted syringates (C3 CS substituted alkyl syringates) and phenols.Sodium percarbonate or perborate are preferred sources of hydrogenperoxide.

Said peroxidases are normally incorporated in the detergent compositionat levels from 0.0001% to 2% of pure enzyme by weight of the detergentcomposition.

Other preferred enzymes that can be included in the detergentcompositions of the present invention include lipases. Suitable lipaseenzymes for detergent usage include those produced by microorganisms ofthe Pseudomonas group, such as Pseudomonas stutzeri ATCC 19.154, asdisclosed in British Patent 1,372,034. Suitable lipases include thosewhich show a positive immunological cross-reaction with the antibody ofthe lipase produced by the microorganism Pseudomonas fluorescent IAM1057. This lipase is available from Amano Pharmceutical Co Ltd., Nagoya,Japan, under the trade name Lipase P “Amano”. Other suitable commerciallipases include Amano-CES, lipases ex Chromobacter viscosum, e.g.Chromobacter viscosum var. lipolyticum NRRLB 3673 from Toyo Jozo Co.,Tagata, Japan; Chromobacter viscosum lipases from U.S. BiochemicalCorp., USA an Disoynth CO., The Netherlands, and lipases ex Pseudomonasgladioli. Especially suitable lipases are lipases such as M 1 Lipase®and Lipomax® (Gist-Brocades) and Lipolase® and Lipolase Ultra® (Novo)which have found to be very effective when used in combination with thecompositions of the present invention. Also suitable are the lipolyticenzymes described in EP 258 068, WO 92/05249 and WO 95/22615 by NovoNordisk and in WO 94/03578, WO 95/35381 and WO 96/00292 by Unilever.

Also suitable are cutinases which can be considered as a special kind oflipase, namely lipases which do not require interfacial activation.Addition of cutinases to detergent compositions have been described ine.g. WO A88/09367 (Genencor); WO 90/09446 (Plant Genetic) and WO94/14963 and WO 94/14964 (Unilever).

The lipases and/or cutinases are normally incorporated in the detergentcomposition at levels from 0.0001% to 2% of pure enzyme by weight of thedetergent composition.

Amylases (a and/or f) can be included for removal of carbohydrate-basedstains. WO 94/02597, Novo Nordis, A/S published Feb. 3, 1994, describesdetergent compositions which incorporate mutant amylases. Se also WO95/10603, Novo Nordisk A/S, published Apr. 20, 1995. Other amylasesknown for use in detergent compositions include both a- and ss-amylases.

Amylases are stability-enhanced amylases described in WO 94/18314,published Aug. 18, 1994 and WO 96/05295, Genencor, published Feb. 22,1996 and amylase variants having additional modification in theimmediate parent available from Novo Nordisk A/S, disclosed in Wo95/10603, published April 95. Also suitable are amylases described in EP277 216, WO 95/26397 and WO 96/23873 (all by Novo Nordisk).

Examples of commercial a-amylases products are Purafect Ox Am&commat;from Genencor and Termamyl&commat;' Ban, Fungamyl&commat; and Duramylo,all available from Novo Nordisk A/S Denmark. WO 95/26397 describes othersuitable amylases; aamylases characterised by having a specific activityat least 25% higher than the specific activity of Termamylt) at atemperature range of 25 C to 55 C and at a pH value in the range of 8 to10, measured by the Phadebas a-amylase activity assay. Suitable arevariants of the above enzymes, described in WO 96/23873 (Novo Nordisk).Other amylolytic enzymes with improved properties with respect to theactivity level of the combination of thermostability and a higheractivity level are described in WO 95/35382.

The amylolytic enzymes are incorporated in the detergent compositions ofthe present invention a level of from 0.0001% to 2%, preferably from0.00018% to 0.06%, more preferably from 0.00024% to 0.048% pure enzymeby weight of the composition.

The above mentioned enzymes may be of any suitable origin, such asvegetable, animal, bacterial, fungal and yeast origin. Origin canfurther be mesophilic or extremophilic (psychrophilic, psychrotrophic,thermophilic, barophilic, alkalophilic, acidophilic or halophilic.)Purified or non-purified forms of these enzymes may be used. Nowadays,it is common practice to modify wildtype enzymes via protein/geneticengineering techniques in order to optimise their performance efficiencyin the detergent compositions of the invention. For example, thevariants may be designed such that the compatibility of the enzyme tocommonly encountered ingredients of such compositions is increased.

Alternatively, the variant may be designed such that the optimal pH,bleach or chelant stability, catalytic activity and the like, of theenzyme variant is tailored to suit the particular cleaning application.

In particular, attention should be focuses on amino acids sensitive tooxidation in the case of bleach stability and on surface charges for thesurfactant compatibility. The isoelectric point of such enzymes may bemodified by the substitution of some charged amino acids, e.g. anincrease in isoelectric point may help to improve compatibility withanionic surfactants. The stability of the enzymes may be furtherenhanced by the creation of e.g. additional salt bridges and enforcingcalcium binding sites to increase chelant stability. Special attentionmust be paid to the cellulases as most of the cellulases have separatebinding domains (CBD). Properties of such enzymes can be altered bymodifications in these domains.

Said enzymes are normally incorporated in the detergent composition atlevels of from 0.0001% to 2% of pure enzyme by weight of the detergentcomposition. The enzymes can be added as separate single ingredients(prills, granulates or stabilized liquids containing one enzyme) or asmixtures of two or more enzymes (e.g. as cogranulates).

Other suitable detergent ingredients that can be added are enzymeoxidation scavengers which are described in Copending European Patentapplication 92870018.6 filed on Jan. 31, 1992. Examples of such enzymeoxidation scavengers are ethoxylated tetraethylene polyamines.

A range of enzyme materials and means for their incorporation intosynthetic detergent compositions is also disclosed in WO 9307263 A andWO 9307260 A to Genencor International, WO 8908694 A to Novo, and U.S.Pat. No. 3,553,139 Jan. 5, 1971 to McCarty et al. Suitable enzymes aredescribed in U.S. Pat. No. 4,507,219 Hughes, Mar. 26, 1985. Enzymematerials useful for liquid detergent formulations, and theirincorporation into such formulations, are disclosed in U.S. Pat. No.4,261,868, Hora et al, Apr. 14, 1981. Enzymes for use in detergents canbe stabilise by various techniques. Enzyme stabilisation techniques aredisclosed and exemplified in U.S. Pat. No. 3,600,319, Aug. 17, 1971,Gedge et al, EP 199,405 and EP 200,586, Oct. 29, 1986, Venegas. Enzymestabilisation are also described, for example, in U.S. Pat. No.3,519,570. A useful Bacillus, sp. AC13 giving proteases, xylanases andcellulases, is described in WO 9401532.

Controlled Rate of Release

A means may be provided for controlling the rate of release of bleachingagent, particularly oxygen bleach to the wash solution.

Means for controlling the rate of release of the bleach may provide forcontrolled release of peroxide species to the wash solution. Such meanscould, for example, include controlling the release of any inorganicperhydrate salt, acting as a hydrogen peroxide source, to the washsolution.

The coating may therefore, for example, comprise material poorlydigestible by the enzyme, or by use of a second coating of sufficientthickness that the kinetics of dissolution of the second coating providethe controlled rate of release. A suitable second coating is any one ofthose described above for the enzyme.

Other means of providing the required controlled release includemechanical means for altering the physical characteristics of the bleachto control its solubility and rate of release. Suitable protocols couldinclude compression, mechanical injection, manual injection, andadjustment of the solubility of the bleach compound by selection ofparticle size of any particulate component.

Whilst the choice of particle size will depend both on the compositionof the particulate component, and the desire to meet the desiredcontrolled release kinetics, it is desirable that the particle sizeshould be more than 500 micrometers, preferably having an averageparticle diameter of from 800 to 1200 micrometers.

Additional protocols for providing the means of controlled releaseinclude the suitable choice of any other components of the detergentcomposition matrix such that when the composition is introduced to thewash solution the ionic strength environment therein-provided enablesthe required controlled release kinetics to be achieved.

Bleaching Agent Coating

The coating material may be applied using various methods. Any coatingmaterial is typically present at a weight ratio of coating material tobleach of from 1:99 to 1:2, preferably from 1:49 to 1:9.

One method for applying the coating material involves agglomeration.Preferred agglomeration processes include the use of any of the organicbinder materials described hereinabove. Any conventionalagglomerator/mixer may be used including, but not limited to pan, rotarydrum and vertical blender types. Molten coating compositions may also beapplied either by being poured onto, or spray atomized onto a moving bedof bleaching agent.

Encapsulation techniques are known for both peroxygen and chlorinebleaches, such as in U.S. Pat. No. 4,126,573.

The coatings can be applied in a variety of well-known methods includingtumbling the coating and coated compound in a rolling mill, spraying asolution or suspension of the coating into a fluidised bed of thecompound to be coated, precipitating the coating from a solvent on tothe compound to be coated which is in suspension in the solvent.

For chlorine bleaches the amount of encapsulates used in thecompositions of the invention may vary within the range of about 0.5% toabout 3% as available chlorine (Avcl). For peroxygen bleaching agents asuitable range will be from 0.5% to 3% avO (available oxygen).

Detersive Surfactant

The detergent compositions of the present invention preferably includesurfactants wherein the surfactant can be selected from the groupconsisting of nonionic and/or anionic and/or cationic and/or ampholyticand/or zwitterionic and/or semipolar surfactants.

The surfactant is typically present at a level of from about 0.01% toabout 60% by weight. More preferred levels of incorporation are fromabout 1% to about 35% by weight, most preferably from about 1% to about30% by weight of detergent compositions.

The surfactant is preferably formulated to be compatible with the enzymeand bleach components present in the composition. In liquid or gelcompositions the surfactant is most preferably formulated such that itpromotes, or at least does not degrade, the stability of any enzyme inthese compositions.

Preferred surfactants to be used according to the present inventioncomprise as a surfactant one or more of the nonionic and/or anionicsurfactants described herein.

Polyethylene, polypropylene, and polybutylene oxide condensates of alkylphenols are suitable for use as the nonionic surfactant of the presentinvention, with the polyethylene oxide condensates being preferred.These compounds include the condensation products of alkyl phenolshaving an alkyl group containing from about 6 to about 14 carbon atoms,preferably from about 8 to about 14 carbon atoms, in either astraight-chain or branched-chain configuration with the alkylene oxide.In a preferred embodiment, the ethylene oxide is present in an amountequal to from about 2 to about 25 moles, more preferably from about 3 toabout 15 moles, of ethylene oxide per mole of alkyl phenol.

Commercially available nonionic surfactants of this type include Igepal™CO630, marketed by the GAF Corporation; and Triton™ X-45, X-114, X-100and X102, all marketed by the Rohm & Haas Company. These surfactants arecommonly referred to as alkylphenol alkoxylates (e.g., alkyl phenolethoxylates).

The condensation products of primary and secondary aliphatic alcoholswith from about 1 to about 25 moles of ethylene oxide are suitable foruse as the nonionic surfactant of the nonionic surfactant s of thepresent invention. The alkyl chain of the aliphatic alcohol can eitherbe straight or branched, primary or secondary, and generally containsfrom about 8 to about 22 carbon atoms.

Preferred are the condensation products of alcohol having an alkyl groupcontaining from about 8 to about 20 carbon atoms, more preferably fromabout 10 to about 18 carbon atoms, with from about 2 to about 10 molesof ethylene oxide per mole of alcohol. About 2 to about 7 moles ofethylene oxide and most preferably from 2 to 5 moles of ethylene oxideper mole of alcohol are present in said condensation products. Examplesof commercially available nonionic surfactants of this type includeTergitol™ 15-S-9 (the condensation product of C11-C18 linear alcoholwith 9 moles ethylene oxide), Tergitol™ 24-L-6 NMW (the condensationproduct of C12-C14 primary alcohol with 6 moles ethylene oxide with anarrow molecular weight distribution), both marketed by Union CarbideCorporation; Neodol™ 45-9 (the condensation product of C14-C18 linearalcohol with 9 moles of ethylene oxide), Neodol™ 23-3 (the condensationproduct of C12-C13 linear alcohol with 3.0 moles of ethylene oxide),Neodol™ 45-7 (the condensation product of C14-C18 linear alcohol with 7moles of ethylene oxide), Neodol™ 45-5 (the condensation product ofC14-C18 linear alcohol with 5 moles of ethylene oxide) marketed by ShellChemical Company, Kyro™ EOB (the condensation product of C13-C18 alcoholwith 9 moles ethylene oxide), marketed by The Procter & Gamble Company,and Genapol LA 030 or 050 (the condensation product of C12-C14 alcoholwith 3 or 5 moles of ethylene oxide) marketed by Hoechst. Preferredrange of HLB in these products is from 8-11 and most preferred from8-10.

Also useful nonionic surfactants of the present invention are thealkylpolysaccharides disclosed in U.S. Pat. No. 4,565,647, having ahydrophobic group containing from about 6 to about 30 carbon atoms,preferably from about 10 to about 16 carbon atoms and a polysaccharide,e.g. a polyglycoside, hydrophilic group containing from about 1.3 toabout 10, preferably from about 1.3 to about 3, most preferably fromabout 1.3 to about 2.7 saccharide units. Any reducing saccharidecontaining 5 or 6 carbon atoms can be used, e.g., glucose, galactose andgalactosyl moieties can be substituted for the glucosyl moieties(optionally the hydrophobic group is attached at the 2-, 3-, 4-, etc.positions thus giving a glucose or galactose as opposed to a glucosideor galactoside). The intersaccharide bonds can be, e.g., between the oneposition of the additional saccharide units and the 2-, 3-, 4-, and/or6-positions on the preceding saccharide units.

The condensation products of ethylene oxide with a hydrophobic baseformed by the condensation of propylene oxide with propylene glycol arealso suitable for use as the additional nonionic detersive surfactant ofthe present invention. The hydrophobic portion of these compounds willpreferably have a molecular weight of from about 1500 to about 1800 andwill exhibit water insolubility. The addition of polyoxyethylenemoieties to this hydrophobic portion tends to increase the watersolubility of the molecule as a whole, and the liquid character of theproduct is retained up to the point where the polyoxyethylene content isabout 50% of the total weight of the condensation product, whichcorresponds to condensation with up to about 40 moles of ethylene oxide.

Examples of compounds of this type include certain of thecommercially-available Plurafac™ LF404 and Pluronic™ surfactants,marketed by BASF.

Also suitable for use as the nonionic surfactant of the presentinvention, are the condensation products of ethylene oxide with theproduct resulting from the reaction of propylene oxide andethylenediamine. The hydrophobic moiety of these products consists ofthe reaction product of ethylenediamine and excess propylene oxide, andgenerally has a molecular weight of from about 2500 to about 3000. Thishydrophobic moiety is condensed with ethylene oxide to the extent thatthe condensation product contains from about 40% to about 80% by weightof polyoxyethylene and has a molecular weight of from about 5,000 toabout 11,000. Examples of this type of nonionic surfactant includecertain of the commercially available Tetronic™ compounds, marketed byBASF.

Suitable anionic surfactants to be used are linear alkyl benzenesulfonate, alkyl ester sulfonate, branched alkyl sulfonate, mid-branchedalkyl sulfonate surfactants including linear esters of Cg-C20 carboxylicacids (i.e., fatty acids) which are sulfonated with gaseous S0₃according to “The Journal of the American Oil Chemists Society”, 52(1975), pp. 323-329. Suitable starting materials would include naturalfatty substances as derived from tallow or palm oil.

Other suitable anionic surfactants include the alkyl sulfate surfactantswhich are water soluble salts or acids of the formula ROS0₃M wherein Rpreferably is a C10-C24 hydrocarbyl, preferably an alkyl or hydroxyalkylhaving a C10-C20 alkyl component, more preferably a C12-C18 alkyl orhydroxyalkyl, and M is H or a cation, e.g., an alkali metal cation (e.g.sodium, potassium, lithium), or ammonium or substituted ammonium (e.g.methyl-, dimethyl-, and trimethyl ammonium cations and quaternaryammonium cations such as tetramethylammonium and dimethyl piperdiniumcations and quaternary ammonium cations derived from alkylamines such asethylamine, diethylamine, triethylamine, and mixtures thereof, and thelike). Typically, alkyl chains of C12-C16 are preferred for lower washtemperatures (e.g. below about 50 C) and C16-C18 alkyl chains arepreferred for higher wash temperatures (e.g. above about 50 C).

Other anionic surfactants useful for detersive purposes can also beincluded in the detergent compositions of the present invention. Thesecan include salts (including, for example, sodium, potassium, ammonium,and substituted ammonium salts such as mono-, di- and triethanolaminesalts) of soap, C18-C22 primary of secondary alkanesulfonates, C18-C24olefinsulfonates, sulfonated polycarboxylic acids prepared bysulfonation of the pyrolyzed product of alkaline earth metal citrates,e.g., as described in British patent specification No. 1,082,179,C18-C24 alkylpolyglycolethersulfates (containing up to 10 mole ofethylene oxide); alkyl glycerol sulfonates, fatty acyl glycerolsulfonates, fatty oleyl glycerol sulfates, alkyl phenol ethylene oxideether sulfates, paraffin sulfonates, alkyl phosphates, isethionates suchas the acyl isethionates, N-acyl taurates, alkyl succinamates andsulfosuccinates, monoesters of sulfosuccinates (especially saturated andunsaturated C12-C18 monoesters) and diesters of sulfosuccinates(especially saturated and unsaturated C6-C12 diesters), acylsarcosinates, sulfates of alkylpolysaccharides such as the sulfates ofalkylpolyglucoside (the nonionic nonsulfated compounds being describedbelow), branched primary alkyl sulfates, and alkyl polyethoxycarboxylates such as those of the formula RO(CH2CH20) k-CH2COO-M+wherein R is a Cg-C22 alkyl, k is an integer from 1 to 10, and M is asoluble salt-forming cation. Resin acids and hydrogenated resin acidsare also suitable, such as rosin, hydrogenated rosin, and resin acidsand hydrogenated resin acids present in or derived from tall oil.

Further examples are described in “Surface Active Agents and Detergents”(Vol. I and 11 by Schwartz, Perry and Berch). A variety of suchsurfactants are also generally disclosed in U.S. Pat. No. 3,929,678,issued Dec. 30, 1975 to Laughlin, et al. at Column 23, line 58 throughColumn 29, line 23 (herein incorporated by reference).

When included therein, the detergent compositions of the presentinvention typically comprise from 1% to 40%, preferably from 3% to 20%by weight of such anionic surfactants.

Optional Ingredients

Optional ingredients that may be used in a detergent composition areselected from; suspending agent, chelating agent, radical scavenger,antioxidant, stabiliser, soil suspending polymer, polymeric soil releaseagent, pH control agent, dye transfer inhibitor, solvent, suds controlagent, suds booster, brightener, perfume, pigment, dyes or a mixturethereof.

When included therein, the detergent compositions of the presentinvention typically comprise from 0.1% to 10%, preferably from about0.5% to 8% by weight of any one, or a mixture thereof, of the optionalingredients listed above.

1. A detergent composition comprising an enzyme and a coated bleachingagent, wherein the coating material of the bleaching agent is asubstrate for the enzyme.
 2. A detergent composition according to claim1 wherein, the composition is a liquid.
 3. A detergent compositionaccording to claim 1 wherein, the material is selected from the groupconsisting of protein, either of animal or vegetal origin, starch, fatand a mixture thereof.
 4. A detergent composition according to claim 3wherein, the material is a protein.
 5. A detergent composition accordingto claim 1 wherein, the enzyme is a protease.
 6. A detergent compositionaccording to claim 1 wherein, the bleaching agent is a halogen releasingbleach or an oxygen releasing bleach
 7. A detergent compositionaccording to claim 6 wherein, the bleaching agent has an average sizefrom 100μ to 2500μ.
 8. A detergent composition according to claim 1wherein, the bleaching agent consists of a hydrogen peroxide source andan organic peroxyacid bleach precursor compound.
 9. A detergentcomposition according to claim 2 wherein, the material is selected fromthe group consisting of protein, either of animal or vegetal origin,starch, fat and a mixture thereof.
 10. A detergent composition accordingto claim 9 wherein, the material is a protein.
 11. A detergentcomposition according to claim 7 wherein, the bleaching agent has anaverage size from 500μ to 2000μ.
 12. A detergent composition accordingto claim 11 wherein, the bleaching agent has an average size from 700μto 1500μ.